Dredging method employing injection and suction nozzles

ABSTRACT

A dredging method and apparatus employing high-velocity directed injector nozzles which hydraulically dislodge and drive discrete bodies of large inertia from a position at rest on an aqueous floor into a cooperating vacuum device which collects such bodies and removes them to another area for further treatment.

United States Patent Beck, Jr. 1 Mar. 7, 1972 [54] DREDGING METHOD EMPLOYING 2,150,799 3/1939 .lacuzzi ..4l7/8l IN ECTION AND SUCTION NOZZLES J '1 FOREIGN PATENTS OR APPLICATIONS 72 I t: Ea .Beck, .,V t ,Calf. I 1 or J en 242,055 9/1969 U.S.S.R. ..37/63 u The Unwed Slates of America as 238,421 7/1969 U.S.S.R. ....37/63' represented y the Secretary of the y 189,133 2/1957 Austria ....37/62 22 Filed; Dec. 17 19 9 833,044 4/1960 Great Britain ..417/84 [2]] PP 885,764 Primary Examiner-Robert E. Pulfrey Assistant Examiner-Clifford D. Crowder 52 us. CL ..37/195, 37/62, 299/8, Amway-4km Sciascia and Baxter Warner 417/80 [51] Int. Cl. ..E02f 3/92 ABSTRACT [58] FieIdofSearch ..37/58,59,6l63, A dred glng method and apparatus employmg high-velocity 37/72, 195, 4l7/84, 79. 80, 31, directed injector nozzles which hydraulically dislodge and drive discrete bodies of large inertia from a position at rest on an aqueous floor into a cooperating vacuum device which col- [56] Reta Cited lects such bodies and removes them to another area for UNITED STATES A S further treatment.

Arkless et al. ..417/81 1 Claims, 3 Drawing Figures PATENTEUHAR H972 v 3.646.694

sum 1 [1F 2 MWIV O INVENTOR E l/PL J. BECK JR.

PAIENIEIJMAR TIHYZ 646,694

SHEET 2 OF 2 DREDGING METHOD EMPLOYING INJECTION AND SUCTION NOZZLES STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to dredging apparatus and a method of dredging and more particularly to cooperating injection and vacuum apparatus useful in removing submerged objects of substantial density and mass. It is of particular value in the recovery of such objects as discrete pieces or nodules of mineral ore from the ocean floor.

2. Description of the Prior Art The prior art is replete with dredging arrangements wherein gravel and fines are churned loose from an aqueous floor. However the purpose of such devices is to keep the fines suspended until they are induced into suction orifices and collected for later use or disposal. Such prior art devices are inherently incapable of selecting and removing objects of substantial density and mass.

SUMMARY OF THE INVENTION The present invention is not concerned with the collection of fines but instead is designed for the recovery of discrete bodies of substantial mass or high density from an aqueous floor by their forceful injection into the inlet or mouth of a vacuum device which is closely associated with the injection apparatus. In operation a fluid medium is drawn rapidly through the vacuum device and associated vacuum equipment and entrains any object forced therein. Thus discrete heavy objects may conveniently be lifted from the ocean floor and transported to a remote location for collection or further treatment.

OBJECT OF THE INVENTION An object of the present invention is to provide a hydrodynamic method and apparatus suitable for removing relatively heavy objects of large inertia, or high mass per unit volume from an aqueous floor.

Another object is to provide a reliable and economic apparatus for dredging heavy, discrete objects from an aqueous environment and for transporting them to a remote point for processing. 7

Other objects, advantages, and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side elevational view showing the present invention on the ocean floor beneath a supporting surface vessel.

FIG. 2 is an enlarged side elevational partial view of a modification wherein a plurality of the present devices are at- 'tached to a supporting framework.

FIG. 3 is an enlarged detailed side elevation with portions broken away of the preferred form of vacuum and injection pressure generating apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT A primary purpose of the present invention is the forceful injection of discrete bodies at rest on the floor of a body of water into an adjacent vacuum device where such bodies are entrained in a rapidly moving fluid medium and removed to another area in order that they may be transported to remote areas for further processing.

Referring now to the drawings wherein like and corresponding parts are designated by similar reference characters, the

present invention comprises an injector nozzle 10 connected by a high-pressure hose or pipe 12 to a pumping arrangement 14 located at a suitable point above the ocean floor. The nozzle 10 is adapted to direct a very strong hydraulic stream, supplied by pumping arrangement ]ld, against discrete objects on the aqueous floor and force such objects into an adjacent flared suction or collection head 16 attached to suction piping 18 which, in the embodiment illustrated, leads to the previously mentioned pumping arrangement 14. A discharge conduit 20 extends upwardly from the pumping arrangement 14 and may connect to a conveyor arrangement at a remote point or may lead into the hold of a ship indicated generally at 21.

The pump supplies fluid under great pressure to pipe 12 which fluid is ejected through nozzle 10 against discrete objects 11 on the ocean floor, such as manganese nodules or the like. At the same time, pump 14 also constantly draws water into the collection or suction head 16. Thus, any object forced into the suction head is first dislodged from the floor without unnecessary entrainment of cohesive sediments by cross currents of turbulent stream flow. Such object is then carried upwardly through pipe 18, pump 14 and exhaust line 20 to the conveying arrangement or ship 21 where it may be further removed to any desired treatment area.

In order to sweep a large area of subaqueous floor, a series of pairs of diametrically opposed injection nozzles 10 and suction heads 16, arranged and functioning as described above, may be attached to any suitable supporting framework 22-23 by pressure and suction conduits l2 and 18 respectively (FIG. 2). Such a device would be highly efficient since it is capable of entraining more than a single object at any one time.

Details of the means employed for supporting the device above the ocean bottom and for moving it thereover have not been illustrated since any suitable means including buoys, booms, draglines and the like may be employed for this purpose.

As shown best in FIG. 3 the pumping arrangement 14 may include an external housing 24 enclosing a bladed rotor 26 of the centrifugal type mounted on shaft 28 and driven by any suitable power means such for example as an electric motor (not shown). Housing 24 may be provided with a central inlet opening 30 through which the suction conduit 18 delivers the lumps picked up by collection head 16. As shown discharge outlet 20 leads from this housing, being tangentially located at the periphery and upwardly directed in order to facilitate delivery of the collected lumps to a remote area such as the hold of ship 21. It will be apparent that with this arrangement centrifugal force aided by the rush of incoming fluid will throw the lumps to the outside portion of the housing whereupon they will be carried upwardly in the stream of fluid issuing from the pump.

In order to supply the injector nozzle with fluid under pressure so that lumps may be directed into the collecting head, pressure line 12 emerges from the housing at a point intermediate the center and the periphery thereof. Of course the location of such point may be varied as desired in order to obtain the maximum output pressure, however such point is preferably so selected that it is inside of the circular peripheral path travelled by the majority of the heavier lumps and thus avoids attempted entry of such lumps into the high-pressure return system. Of course a suitable screen 32 may also be provided at the point where the conduit 12 emerges from the housing to preclude undesired entry of large lumps into the return line 12.

With the foregoing arrangement there is provided means whereby a relatively strong stream of fluid is directed against lumps such as nodules of ore or the like to impel them towards the collecting head so that they may be entrained within the flow of fluid through suction conduit 18 leading to the center of the pump housing 24. From there the powerful centrifugal force impels such lumps to the outside area of the housing from which they are readily thrown tangentially upwardly in the flow of fluid through discharge conduit 20. A slotted grill formed by a row of depending fingers 34 assists in directing such lumps upwardly and aids in breaking up any larger lumps which may be quite friable.

Though the discharge line 20 ordinarily can lift lumps of relatively heavy weight, means may be provided to increase this lifting capacity by inserting into the injector line 12 suitable flow control means, such as valve 36, which may be controlled by a valve-actuating and timing means 38 or by remote control means periodically to reduce or terminate flow through pressure conduit 12. The effect of such periodic change in velocity of flow is effectively to increase, for a short period, the volume of upward flow of fluid through discharge conduit 20 so that upward movement of entrained lumps is periodically accelerated.

Any suitable valve means for controlling flow within high pressure conduit 12 may be employed, however such means should preferably not be of a type affected by abrasives or the small particles which may pass through screen 32. Hence such valve means may be a shutter or vane that protrudes into the duct, may be the provision of a collapsible flexible portion in such conduit or may be the imposition of hydraulic counterflow therein, all of which is well known in the art of controlling flow of hydraulic fluid through a conduit.

Of course valves 36 may also be incorporated in the multinozzle arrangement of FIG. 2 where they are designated 37 and are controlled by actuating and timing means 39. The valves 37 may be operated either together for simultaneous operations or in sequence so as to control the flow through the conduits in various ways.

The prime mover for rotating shaft 28 of the pump 14 may be an electric, hydraulic, pneumatic or other suitable device.

In the electric device shown it may derive power from a line 4042 which is also employed to operate timer 38 through line 44.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim: l. The method of removing discrete lumps of substantial mass from the sea floor through the application to diametrically opposite sides thereof of hydraulic pressure differentials of sufi'rcient magnitude to cause movement of the mass comprising:

creating a relatively low pressure area on the side of the mass toward which it is desired to cause the mass to move,

concurrently creating on the diametrically opposite side of said mass a relatively high pressure condition away from which it is desired to cause the mass to move,

said pressure conditions being completely additive and of sufficient magnitude to impel movement of said mass in the desired direction,

entraining said mass in an upwardly flowing flow of fluid so as to transport said mass to a new site, periodically accelerating the flow of fluid moving upwardly to temporarily increase the mass-carrying capacity of said flow, and concurrently reducing the magnitude of said highpressure condition during such temporary period. 

1. The method of removing discrete lumps of substantial mass from the sea floor through the application to diametrically opposite sides thereof of hydraulic pressure differentials of sufficient magnitude to cause movement of the mass comprising: creating a relatively low pressure area on the side of the mass toward which it is desired to cause the mass to move, concurrently creating on the diametrically opposite side of said mass a relatively high pressure condition away from which it is desired to cause the mass to move, said pressure conditions being completely additive and of sufficient magnitude to impel movement of said mass in the desired direction, entraining said mass in an upwardly flowing flow of fluid so as to transport said mass to a new site, periodically accelerating the flow of fluid moving upwardly to temporarily increase the mass-carrying capacity of said flow, and concurrently reducing the magnitude of said high-pressure condition during such temporary period. 